When we're using PR KVM we must not allow the CPU to take interrupts in virtual mode, as the SLB does not contain host kernel mappings when running inside the guest context. To make sure we get good performance for non-KVM tasks but still properly functioning PR KVM, let's just disable AIL whenever a vcpu is scheduled in. This patch fixes running PR KVM on POWER8 bare metal for me. Signed-off-by: Alexander Graf <agraf@xxxxxxx> --- arch/powerpc/kvm/book3s_pr.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 03fc884..cdc0eef 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -71,6 +71,12 @@ static void kvmppc_core_vcpu_load_pr(struct kvm_vcpu *vcpu, int cpu) svcpu->in_use = 0; svcpu_put(svcpu); #endif + + /* Disable AIL if supported */ + if (cpu_has_feature(CPU_FTR_HVMODE) && + cpu_has_feature(CPU_FTR_ARCH_207S)) + mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~LPCR_AIL); + vcpu->cpu = smp_processor_id(); #ifdef CONFIG_PPC_BOOK3S_32 current->thread.kvm_shadow_vcpu = vcpu->arch.shadow_vcpu; @@ -91,6 +97,12 @@ static void kvmppc_core_vcpu_put_pr(struct kvm_vcpu *vcpu) kvmppc_giveup_ext(vcpu, MSR_FP | MSR_VEC | MSR_VSX); kvmppc_giveup_fac(vcpu, FSCR_TAR_LG); + + /* Enable AIL if supported */ + if (cpu_has_feature(CPU_FTR_HVMODE) && + cpu_has_feature(CPU_FTR_ARCH_207S)) + mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_AIL_3); + vcpu->cpu = -1; } -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
